# useMemo

<EpicVideo url="https://www.epicreact.dev/workshops/react-performance/usememo/solution" />

👨‍💼 Wow! That's a significant improvement!

🦉 Even with this improvement, it seems like React is doing a lot of extra work
to just rerender our app and ultimately do nothing. Remember that when built for
production, React will do much less work and things look even more favorable for
us. Feel free to check the built version of the app if you're curious what this
looks like:

```sh nonumber
npm run build
npm run preview
```
